A touch display device, such as a portable touch display device like a cell phone or a tablet computer, normally includes a touch panel. The touch panel increases in size with the enlargement of the display panel. The increasing in size of the touch panel and the display panel leads to a rapid increase in power consumption of the touch display device.
Besides, all areas of the current touch display panel always have a consistent touch resolution. However, different operating environments require different touch resolutions. For example, a higher touch resolution is required in some operating mode, such as a mode of modulating a picture color or a mode of writing with meticulous stylus.